Using mu4e, I am using SMTP to send emails through my Office 365 server (I don't like it either). When a message is created by mu4e, a file is created in my "Sent" folder, but then the email server creates another email in the same folder leading to duplicate messages on both my local maildir and the remote server when I eventually synchronize.
I resolved the issue somewhat by creating a separate folder for mu4e, "mu4e-Sent", where local messages are moved to once they are sent. This folder is then not synced with the server and I don't have any duplicates there. But I still have duplicates in my local maildir that appear when searching for emails.
Is there a better way to resolve this? Is there perhaps a way to tell mu4e to ignore the local "mu4e-Sent" folder?